Apparatus for continuous contact duplication

ABSTRACT

Apparatus for contact duplicating information carried by a continuous moving master strip onto a continuous moving duplicate strip, exemplified by a diazo roll film duplicator. The duplicate strip is driven from a point downstream of its separation from the master strip and carries the master strip by electrostatic attraction. An expandable film carriage in the processing chamber can be adjusted so as to maintain uniform residence time in the processing chamber. An integral charge assembly is provided which is releasably secured to the apparatus housing to provide ready changing of charge rollers for different strip sizes. The charge assembly incorporates an aligned rotational electrical contact mechanism, chamfered guide roller flanges for easy loading, and an ejection lever. Electrostatic charge is applied by moving the strips between a pair of high voltage rollers, the opposite edges of at least one of the rollers being cut away to increase the air path length. One of the rollers has an outer compliant surface and is carried by a yoke biased toward the other roller under adjustable tension. Various embodiments are provided to accommodate varying strip widths including a rotary elongate lamp assembly, an expandable alignment guide, variable width buffers and a variable width continuous strip loop chamber.

United States Patent [191 Erech et al.

1 1 Dec. 17,1974

[ APPARATUS FOR CONTINUOUS CONTACT DUPLICATION [76] Inventors: Roger A. Erech, 1980 Meadow View Ct., Thousand Oaks, Calif.- 91360; Charles ll. Dietz, 18833 Killoch Way, Northridge, Calif. 91324; Markvard Hauerbach, 19649 Green Mountain Dr., Newhall, Calif. 91321 [22] Filed: Oct. 30, 1972 [21] Appl. No.: 302,383

Related US. Application Data [62] Division of Set. No, 170,186, Aug. 9, 1971,

abandoned.

52 us. C1. 355/84 [51] Int. Cl. G03b 27/10 [58] Field of Search ..-355/48, 50, 67, 84, 104, 355/108, 110, 111

[56] References Cited A UNITED STATES PATENTS 3,379,112 4/1968 Cranskens 355/110 Primary Exam iner.lohn M. l-loran Attorney, Agent, or Firm-Nilss0n, R0bbins, Bissell, Dalgarn & Berliner [57] ABSTRACT Apparatusfor contact duplicating information carried by a continuous moving master strip onto 'a continuous moving duplicate strip, exemplified by a diazo rollfilm duplicator. The duplicate strip is driven from a point downstream of its separation from the master strip and carries the master strip by electrostatic attraction. An expandable film carriage in the processing chamber can be adjusted so to maintain uniform residence time in the processing chamber. An integral charge assembly is provided which is releasably secured to the apparatus housing to provide ready changing of charge rollers for different strip sizes. The charge assembly incorporates an aligned rotational electrical contact mechanism, chamfered guide roller flanges for easy loading, and an ejection lever. Electrostatic charge is applied by moving the strips between a pair of high voltage rollers, the opposite edges of at least one of the rollersbeing cut away to increase the air path length. One of the rollers has an outer compliant surface and is carried by a yoke biased 'to-' ward the other roller under adjustable tension. Various. embodiments are provided to accommodate vary ing strip widths including a rotary elongate -.lamp assembly, an expandable alignment guide, variable width buffers and a variable width continuous strip loop chamber.

1 Claim, l5 Drawing Figures I This invention generally relates to contact duplication apparatus. The advent of information storage, particularly from computer output devices, on microfilm and microfiche has given rise to the need for rapidly and inexpensively producingduplicates of such microfilm information. The information may be stored on film strips varying in width from 8 'mm for certain types of microfilm to 9.5 in. for microfiche. In typical prior art devices film strips-are wound. around idlers andaround a portion of a drum to bring the emulsions in face to face contact; Such arrangements are not satisfactory because the film's are exposed in a non-planar zone which causes optical distortion resulting in a loss of resolution of. the duplicate. Moreover, problems of synchronization and registration arise because the duplicate and master. films'travel'over different distances as a result of differences in their radial spacing from the center of the drum, causing slippage and misregistra- I tion problems. Film tension generated by such devices canicausethe films tostretch, curl and break.

To overcome these difficulties, various devices have been'provided .in which the strips are moved through a planar exposure zone andare maintained in registry by the application of a vacuum between the stripsfor compressing the strips through atmospheric pressure, or by the application of high pressure air, thereby preventing relative longitudinal movement between the strips. One example of thevacuum'type device is disclosed in U.S. Pat; No. 3,468,606. An example of .a high pressure fluid type of device is disclosed in U.S. Pat. No. 3,161,120.

Other patents of interest herein are U.S. Pat. Nos. 2,408,310, 2,569,793,- 3,054,339, 3,057,275, 3,120,163, 3,148,600, 3,161,120, 3,168,022, 3,169,465, 3,308,731, 3,320,867, 3,437,336 and 3,468,606. While theses'ystems function satisfactorily undernormal conditions, they suffe'rthe disadvantage of requiring complex fluidpressure systems including motors, pumps, regulators, pressure switches, solenoid valves, air tanks, filters, and the like. Notonly do the fluid systems increasethe complexityand therefore the I initial cost of the apparatus'but reliability and maintenance are not always satisfactoryuMoreover, there are as a practical matter limits to the .pressure contact which can be otained through the fluid'p ressurizing sys tems which may affect the compressiveor "adherence force providing the registration. Registration problems can become particularly acute where high reduction in image size, common to microfilm and microfiche, place great demands on optical. resolution during'printing.

These problems of fine resolution are increased by the requirement of high processing speedssoas to keep pacewith film produced by film computer output devices. A more recently suggested "means for maintaining master and duplicatestrips in registration during movement is byelectrostaticallychargingthe two strips so that'they' strongly attractone another. and prevent movement therebetween. Such devices allow movement of the strips through a planar exposure zone and avoid the complexity of components required for fluid pressure systems. implementing components in partic- 1m, 4 The present invention provides contact: duplication apparatus utilizing electrostatic charge to attract and closely adhere master and duplicate strips and provides a variety of implmenting components and systems r'esulting in a duplicator of exceptional reliability and economy in construction and use. ln-praticular, various novel components and systems are provided for utilization of the apparatus with a variety of strip sizes.ln operation, a duplicate strip is fed from a. supply reel into contact with a master strip fed from a supply reel or from a continuous loop supply. The strips are electrostatically charged and then moved through an exposure station and thereafter separated, the master strip being returned to a take-up reel or. to a loop chamber. The duplicatestrip passes'in'to an expandable carriage contained in a processing chamber and from-there travels to a take-up reel. Pressure differential buffersare provided adjacenteach supply and take-up station to' apply small constant tension to the strips and to isolate the reel motors.

In a particular embodiment only one of the strips is driven, the other strip being carried throughthe exposure station by electrostatic attraction to the driven du plicate strip. Means-are provided to coordinate the speed of travel of the strips with the expansion or contraction of the expansion carriage so as to maintain a crease the length of the air path to theother roller. One

uniform'residence time in the processing chamber. ln anumber of further embodiments, an integral charge assembly'isprovided which is .releasably' secured. to the apparatus housing to'provide"ready chan ing of charge andalignment rollers for different strip sizes. The assemblyincorporates a projectng alignment member to accurately seat the assembly, an aligned rotational electrical contact mechanism, chamfered guide roller flanges'for easy loading, magnetic securement to the apparatus housing and an ejection lever.

Electrostatic charges are applied by'movin'g the'strips 7 between a pair of high voltage rollers, the opposite edges. of a least one of the rollers being cut away to inof the rollers has an outer compliant surface carried by a yoke and is biased toward the other rollerunderad justable tension. Y

. Various other embodiments are provided to accommodate varying strip widths, including arotary elon- V gate lamp assembly to more rapidly process narrow widths, an expandable downstream alignment guide, variable .width pressure difierential buffers and a variable width continuous master loopchamber. Air turbulence is provided in the loop chamben'a portion of Y which is utilized as an air-blast to bias the-master strip loop intoits buffers.

While the invention is-exemplifiedbycontactprinting apparatus utilizing a master photographic film and light sensitive duplicate film, theprinciples and components arealso applicable to magnetic tape contact duplication wherein electromagneticradiation in the thermal range, rather than'the visible light range, isutilized. For. purposes of convenience and'description, the term master is used to mean any'information bearing strip which isnot substantially affected by the conditionsof, exposure; and which can be utilized to impart suchinformationto a duplicate strip. The tenn dup1ica'te.is used to mean an initiallyunprocessed strip of material whichis sufficientlysensitive to the conditions of-exposure to be modified in accordance with the infomiation on the master strip and can be, for example, diazo film, silver halide emulsion film, low Curie point magnetic tape, or the like. In the apparatus exemplified by the drawings and descriptive portion of the specification, the master strip is an image bearing, otherwise transparent dielectric flim and the duplicate is a lightsensitive dielectric material of the diazo type. The term master is also used to refer to one or more pieces of material in contact with a single duplicate, for example, two master strips of 16 mm film in side by side contact with a duplicate strip of 35 mm film.

I BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevation view of an exemplary embodiment of a contact duplicating apparatus constructed in accordance with the present invention and including a control circuit shown in schematic overlay;

charge rollers utilized herein;

FIG. 7 is a schematic perspective view of a lamp assembly utilized herein;

FIG. 8 is a sectional view taken along the line 88 of FIG. 7, in the direction of the arrows;

FIG. 9 is a schematic perspective view of the lamp .assembly of FIG. 7- in a different rotational disposition;

FIG. 10 is a schematic top view, in partial cross section; of an alignment guide utilized herein;

FIG. 11 is a schematic top view of a portion of the strip transport including the alignment guide of FIG.

FIG. 12 is a schematit'front elevation view, partly in section, of a pressure differential buffer utilized herein;

FIG. 13 is a sectional view taken along the line 13-13 of FIG, 12, in the direction of the arrows;

FIG. 14 is a schematic front elevation view of a loop chamber utilized herein; and

FIG. 15 is a sectional view taken along the line l5-l5 of FIG. 14, in the direction of the arrows.

DETAILED DESCRIPTION such as silver halide emulsion films, low Curie point magnetic tape, and the like.

Referring now to FIG. 1, there is illustrated an exemplary embodiment of an apparatus for contact printing of a duplicate light sensitive continuous duplicate strip 4 10 from a transparent image-bearing continuous master strip 12. The apparatus includes'a housing having a front panel 14 supporting components for transporting and exposing the master and duplicate strips 10 and 12. In this illustration the master strip 12 is a continuous loop of film contained in a loop chamber 16, but shafts 18 and 20 are provided for supply and take-up reels, shown in shadow at 22 and 24. The loop chamber 16 includes a top wall 26 defining an exit 28 and entrance 30 adjacent drive reels 32 and 34 operatively connected to the reels 18 and 20 to rotate therewith so that either loop or reel to reel mode of operation can be utilized without modification to the transport mechanism. In either case, the master film'l2 is led through a pressure differential buffer chamber 36 of the vacuum type,

through an electrostatic charge assembly 38, an exposure zone 40, around a separation roller 42, through another buffer chamber 44, and then back into the loop chamber 16. Y

The duplicate strip 10 is led from a supply reel 46 through a vacuum buffer chamber 48 into contact with the master strip 12 at the electrostatic charge assembly 38, through the exposure zone 40 while in close contact with the master strip 12 and after separation therefrom onto astrip drive 50, into a processing chamber 52, fromthere through a vacuum buffer chamber '54 and onto a take up reel 56. Various of the components in volved in the transporting exposure and processing will be described hereinafter in more detail.

Six separately controlled motors are associated with the apparatus to separately control the duplicate strip supply and take-up reels 46 and 56, the master strip supply and take-up reels 18 and 20, or associated loopdrive shafts 32 and 34, and to top and bottom drives 50 and 51. Each drive 50 and 51 is formed of drive rollers and geared adjacent rollers defining S-lock drives. The take-up and supply reels and shafts are controlled by the length of strip forming loops in the respective vacuum buffer chambers 36, 44, 48 and 54 so as to supply andtake up the strips in accordance with the speed of travel of the strips through the apparatus. At each buffer chamber, vacuum applied at one end draws thestrip past an array of apertures behind which are located a series of reed switches. The reed switches are pro- I grammed so that the adjacentreel is advanced or retarded to maintain a preselected length of strip within the buffer loop, all in accordance with techniques well known to the art. Other means for. sensing the length of the loopsto conrol the speed of the reels can be used and a variety of electromechanical and electrooptical devices are known. i

In an embodiment of this invention, the bottom drive 50 is a tachometer drive, connected to the speed control (hereinafter described) and'constitutes-the sole motive force for transporting the duplicate strip 10 and master strip 12 through the charge assembly 38 and exposure zone 40. Prior art devices have driven both duplicate and master strips while in contact by winding both strips around. a drive roller which, as above pointed out, because of the difference in their radial spacing from the center. of the roller, results in slippage and misregistration problems. The present construction avoids these problems by driving only the duplicate strip 10, the masterstn'p 12 being carried by the dupli-- cate strip 10 by electrostatic adherence.

The duplicate film in this illustration is of the diazo type requiring development with ammrnonia and such processing occurs in the chamber 52. Referring to FIG. 2, there is illustrated an expandable carriage or load elevator 58. The carriage 58 includes a toparray 60 of cantilever idler rollers spaced from a bottom array 62 of similar rollers. The top array 60 is carried by a frame member 64 which is connected on each side to rear channel slides 66 and 68. The bottom roller array 62 is cordingly, in an alternative embodiment, thecarriage 58 isexpanded in accordance with thespeed of the strip to obtain such uniform residence. In this embodiment, the reed switches 73 are onlya pair in a larger array of reed switches 103. When'a change in speed is desired a signal is transmitted-to the reed switch array 103, as indicatedby the dashed line'l05, in'correspondence to the new speed selected. The switches are programmedto control the top drive 51 (via line 75) at a speed providingthe proper differential to maintain a length of strip in the processor appropriate to the ta-.

chometer drive 50 speed. In place of reed switches, one

with the top and bottom roller arrays 60 and 62 closely spaced, thereby minimizing the leader length required for threading the film, and this position is illustrated in solid lines in the drawing. After loading, the locking member 69 is tripped by its solenoid upon starting the apparatus. The rollers 60 and 62 are expanded'to positions indicated by dashed lines 85 and 87 as determined by the differential in speed between the tachometer drive 50 and top drive 51. To establish this differential,

the shaft 65 carries a magnet 71 at its lower end which magnetically actuates; one or the other of a pair of spaced reed switches 73 which provide a signal to the, top'drive, as indicated by the dashed line 75,to retard or advance to maintain the .rnagnet'71 between the switches 73. In use, the duplicate strip 10' is threaded through the roller arrays 60 and 62,-as illustrated in FlGfl so that the bottom roller array'62 is supported via the duplicate strip l0by the top roller array 60. The end members 72 and 74 connected to the bottom roller can use a potentiometer driven by the shaft 65.

Referring now to FIGS". 3-6, components of the elec-- trostatic charge assemblyare illustrated. There is provided an integral alignment and charge assembly 38in which alignment and charge rollers of apredetermined width are carried and which is designed for plug in operation so that when it is desired to utilize the apparatus for a difierent film size, one need merely .remove the integral charge assembly 38 and. replace it with another assembly incorporating guideand charge rollers of the desired width. In this regard, the rollers shown in FIGS.

4, 5 and 6 have different widthsizes to. illustrate the variability of roller sizes thatcan be accommodated.

With specific reference to FIGS. 3 and 4, the duplicate and master strips l0 and 12 are threaded between a pair of guide rollers 106 and I108 for lateral alignment of the strips and are then fed between a pair of charge rollers 110 and 112. The top charge roller 110 is formed with an .outer compliant surface of conductive rubber for maintaining close contact between the rolarray are weighted tojbiasthe carriage 58 to an open position. This bias isbalanced by the tension resulting from the speed differential between the tachometer drive and the top drive 51', placing the roller arrays and 62 at the positions indicated by dashed lines and;87, respectively. I

In furtherance of this embodiment, arid referring back to FIG. 1, a speed control module 86 is provided including a'control panel 88 which is connected to themotors controlling the supply and take-up reels and shafts 18-32, 20-34, 46 and 56 and to the motors controlling the drives 50 and 51. The control panel 88 includes a variety of speed designations digitally variable from 15 feet per minute to 150 fee't per minute. The speed control circuit is shownin schematic overlay at 90 and it is seen that when a new speed is selected the signal thereof is simultaneously transmitted to the 'motor for the tachometer drive 50 and to the motor for the drive Sl-controlled by the reed switches 73. When a greter speed is desired, a signal thereof is transmitted, as indicated by the arrows and 101 to the tachometer and top drives, the top drive being modulated by the reed switches 73 to maintain the speed differential between the drives 50 and 51soas to maintain the roller arrays 60 and 62 at full expansion, indicated at 85 and 87.

In a diazo duplicator, excess ammonia overthat required for development will not harm the film. However, in a duplicator requiring thermal processing, the residence time in the processor should be uniform. Ac-

lers and the outer surfaces of the sandwiched duplicate and master strips 10 and 12 (see FIG-6). The top roller l10'is carried in yoke fashion by a pair of resilient spring bars 114 and 116 onits opposite ends and each spring bar is secured to the underside of an adjustment bar 118. The adjustmentbar 118 is formed rearwardly with a bearing 126 and with a notched cam surface 122 which engages a spring loaded lock .bar 124. Rotation of the adjustment bar 118 in its bearing 126 moves the I lock bar laterally and then back, as indicated by the ar-' row, to successively engage notches in the cam surface 122, locking the spring bars 114 and 116 in a desired position. By rotating the adjustmentbar 118, counterclockwise in its bearing 126, the top charge roller can be lifted from the bottom charge roller to release 'the duplicate and master strips 10 and 12. This permits side loading of a pre-spliced closed master loop.

By rotatingthe adjustment bar 118 clockwise, in-

creasing bias can be applied to the top roller 110 to increase the tensiononthe'sa'ndwiched duplicate and master strips 10' and 12. This feature, in conjunction with the utilization of a conductive rubber roller surface, or other compliant surface, allows very close contact between the confronting surface of the duplicateandmaster strips 10 and 12 during application of the charge potential. Importantly, the oompliant'surface permits the application of a positive bias by compensating for irregularities, such as the occurrence of labels on microfiche film. Furthermore by applying spring force at each end of the top roller, cantering of the bottom roller 112" can be accommodated. Without such accommodation, the bottom and top rollers 110 and 112 would have to be secured in perfect parallel alignment so as to assure proper contact between the duplicate and master strips 10 and 12.

The integral alignment and charge assembly 38 must be accurately secured to the housing in alignment with other guide components and with the duplication zone 40. Securement means must be accessible from the front of the housing so that the assembly can be rapidly replaced. Furthermore, provision must be made for voltage hookup to each charge assembly. Referring to FIG. 4, and back to FIG. 1, the housing panel 14 supports a narrower elongate panel 128 across its width and this, in turn, is utilized to support other, compo"- nents including the control panel 88. The panel 128 is formed with an opening 130 through which extend coupling components carried rearwardly of the charge assembly 38. Referring additionally to FIG. 6, the lower roller 1 12 is secured to an axle 132 forrotation therewith and which extends rearwardly of the charge as inner flange 158 and an outer flange 160 for retaining at 162 to a reduced diameter outer surface. The chamfered alignment flanges operate in conjunction with the planar exposure station 40 and front loading carriage sembly 38 as shown'by the dashed lines 132 in FIG. 4.

The axle is supported in a bearing housing 134 which in turn is supported within an aperture 136 defined in alignment therewith in the housing panel 14'. The axle 132 terminates in a rounded tip 138 which bears againsta resilient electrical contact member 140 carried rearwardly of the housing panel 14 adjacent the aperture 136. The contact member 140 serves as an electrical brush for the axle 1'32 transmitting high voltage thereto and is connected to an electrical supply. The'top roller 110 is connected 'by its bearing to ground, as illustrated schematically in FIG. 6. The electrical' supply is a DC voltage source in the range of 7 4000-8000 volts with a current of a few microamperes.

The charge rollers therefore create a potential across the film strips so as to produce opposite electrostatic surface charges on the strips which will cause strong attraction and adherence therebetween.

r Referring additionally to FIG. 5, the charge assembly tion of the strip edges and will additionally eliminate 38 includes a base plate l42'carrying a disk shaped magnet 144 on its rear side positioned so as to contact I a region of the housing panel 14, which is. constructed of magnetically conductive material. v

The outer edges of the charge assembly base plate 142 are keyed, as indicated at 145, to matin'gly engage the elongate panel 128 adjacent the opening 130 to 'facilitate alignment of the charge assembly 38.

Referring again specifically to FIG. 4, the adjustment bar 118 is arranged so that its rear edge 146 abuts the housing panel 14. A bore 148 is formed lengthwise through the adjustment bar 118 and fits over a projecting alignment sleeve 119 which is secured rearwardly through the housing panel 14 and which is formed with a closed end 121 in the panel 14. The projecting sleeve in conjunction with the aperture 136 serves to rigidly secure andsupport the assembly 38 in proper alignment. A push rod 150 is disposed through the bore 148 and sleeve 119. with its rear end 152 in contact with the sleeve end 121. The bore 148 opens forwardly into a wider diameter bore 153 to accommodate a push button 154 attached to the forward end of the push rod 150; A spring 156 is disposed around the push bar 150 in the wider bore 152 to return the push button 154 to an extended position. In operation, one grips the knurled adjustment bar knob 120 pushing the push button 154 with his thumb, which serves to overcome the force of the magnet 144, dislodging the charge assembly 138 fromthe' housing panel 14.

Referring to FIGS. 3 and 5, the charge assembly alignment rollers 106 and 108, as illustrated by the wider roller 106' in FIG. 5, are each formed with an 58 (FIG. 1) to allow virtually straight through threading.

It has been found that when the contact rollers are equal in width to the width of the film strips passing therebetween a sparkover may resultthrough an air path between the ends of the rollers. The resistance to sparkover or breakdown of the air path between the electrically conductive roller ends depends upon humidity and altitude conditions. Since the resistance to sparkover is a function not only of the dielectric constant of the path over which the potential is impressed,

but is also a function of the distance between the electhe rollers is increased by cutting away opposite edge portions 166 and 168 from the conductive rubber roller so that its resultant opposite edges 168 and 170 are spaced inwardly a distance sufficient to increase the length of the air path to the'adjacent edges 172 and I 174 of the lower roller 112', thereby preventing sparkover. Suppression of sparkover will preclude degradascintillation which could have an adverse effect upon a light sensitive duplicate strip.

Referring nowv to FIGS. 7-9, there is illustrated another embodiment of the invention. In the processing of relatively wide strips of light sensitve material, such 1 as a strip of microfiche 176 (FIG. 7), a relatively wide light beam is required to .properly expose the strip along its entire width. On the other hand, when it is desired to process relatively narrow widths of film, such as 35 mm microfilm 178 (FIG. 9), only a narrow beam of light is required. In accordance with another embodiment of the invention, the reflector isconformed to the film size so as to apply a beam width commensurate with the film size. In the embodiment illustrated in FIGS. 7-9,-the same lamp'assembly is utilized for exposing both wide strips and narrow strips, but is rotated 90 when used with narrow strips so that the reflector exposes a greater length of the narrow strip than would otherwise be'exposed. Accordingly, a bonus in processing speed is obtained allowing narrower widths of light sensitive strip tobe processed at a substantially faster rate than otherwise possible. Referring to FIGS; 7 and 8, a lamp assembly 180 is, illustrated including a 2000 watt mercury arc lamp 182 and reflector 184 therefor enclosed by a housing 186 defining an exposure region 188, protected by a plate of glass. The exposure region 188 has a substantially greater length dimension than width dimension.- In FIG. 7, the housing is secured with its width dimension along the line of travel of the strips,

tated 90 so as to be secured with its length dimension along the line of travel of the strips 178, as indicated by the arrow 196, thereby exposing a greater length of the narrower strip 178. In place of a mercury arc lamp, one can utilize any lamp whichis compatible with the type of film being used in the duplication operation. Furthermore, a plurality of lamps canbe contained within the lamp housing. Other means for conforming the re-- flector can be utilized,1such as by changing the shape of the reflector.

Referring now to FIG. 10 in conjunction-with FIG. 1,

there is illustrated an alignment guide 198 which is disalignment guide 198 includes an upright idler roller 200 carried by a support shaft 202 extending crosswise of the duplicate and master strips, indicated by dashed lines at 204. The supportshaft 202 extends through a sleeve 206 supported rearwardly of an opening 208 formed in the housing panel 14. The shaft 202 is formed with a series of notches'210 spaced in accordance with the standard strip widths from l6 mm to I mm. A spring loaded bullet catch-212 carried rearwardly of the housing panel 14 communicates through an opening 214 in the sleeve 206 with selected notches to secure the lateral alignment guide 198 in position.

To change the strip width'accommodated by the alignment guide 198, one 'merely has to pull out or push in the support shaft 202, as appropriate, as indicated by the arrow 216, until the proper notch-210 is secured by the bullet catch 212. The lateral alignment guide 198 aids in assuring proper registration. for exposure. It

serves in conjunction with the alignment and electrostatic charge assembly38 to eliminate a carrier or transport device for the strips while in the exposure zone, minimizing problems of scratching or rubbing between strips and a carrier, and eliminating problems of reflection when the srips are transparent. An idler roller 215 (FIG. 1) spaced just downstream of the alignment guide 198 aids in this support.

Referring to FIG. 11, a further'aspect of the align ment roller 198 is illustrated. The bottom charge roller 112 is formed with side flanges which must be set apart a distance sufiicient to accommodate the maximum toleranc'e of the type'of strips and 12 utilized. As a reposed downstream of the exposure station 40. The

tures226 communicates with a'vacuum source, not

shown, carried rearwardly of thehousing panel 14.-'I 'he buffer includes a front wall 228 which may be transparvent and which is disposed between the side walls 220 and 221. The side walls 220 and 221 are lined with felt '230'an'd 232 or other soft material to prevent damage to the film and to serve as an air sea] with the side edges of the front wall. The front wall si snugly tit against the lining 230 and 232 and can slide toward and away from the rear wall 222, as indicatedby 'the arrow 224-. The side walls 220 and 221 are formed along lines below the felt linings with keyways 236 and 238 and are each formed vvitha series of notches 240 and 242 within the keyways. A spring loaded latching member 244 is carried exteriorly of the front wall 228 for engagement in the keyways withthe notches 240 and 242. Release bars 246 communicate with the spring catches and are formed to release the catcheswhen pressed together.

In the configuration illustrated in FIGS: Hand 13, the front wall is at its most extended position to accommodate the widest strip 10 and in such position is closely adjacent'the forward edge of the strip 10 while the rear wall 222 is closely adjacent therear edge of the strip 10. When it is desired to utilize a narrower strip, one need merely press the release bars 246 together and push the front wall 228 to the desired position, the

' spring latching member 244 engaging the appropriate notches 240 and 242, such modified configuration being shown by dashed lines at 248.

' Referring to FIGS. 14 and 15 there is illustrated an pressure differential buffer, which may be any of the buffers 36, 44, 48 or 54 illustrated in FIG. 1. The buffer includesa housing 216 open at one end and defining a strip entrance and exit region 218 thereat. The housing includes opposite side walls 220 and 221 in the width plane of an enclosed strip, e.g., aduplicate strip 10.

The side walls 220 and 221 are somewhat wider than the widest strip to be processed. A rear wall 222 is secured between the side walls and airtight therewith, and is formed'with a series of apertures 224 aligned with reed switches for controlling the speed of an associated reel, as hereinbefore described. One of the aperexpandable loop chamber 16 for containing varying widths of a master strip'loop 12. The rear wallof the loop chamber is defined by a panel 250 carried by the contact duplicator housing. The loop chamber includes a pair of opposite side walls 252 and'254 in the width plane of the enclosed length of master strip 12 and having a width at least as wide as the widest strip width to be accommodated. As previously noted, the loop chamber includes a top wall 26 defining a strip exit 28 and entrance 30. The chamber includes a front wall 256 which may be transparent and which is carried by opposite pairs of drawer slides disposed inchannels 258, shownby dashedlines in FIG. 14 and in shadow in FIG. 15, formed in adjacent housing walls 260 and 262. Suitable detents are provided as known in the drawer art to stop the front wall 256 at any of a number of selected positions corresponding to various strip widths. When adjusted for a particular'strip width, the front wall 256. is closely adjacent the forward edge of the strip 12 therein while the rear wall 250 is closely adjacent the rear edge of the strip 12. The top edge of the front wall is spaced somewhat below the top wall 26 so that it can be moved therebeneath. The front wall carries a'bottom wall'264 which can be extended below the bottom ledge 266 of the housing. A handle bar 268 is strung across the front wall. To accommodate a difv ferent width strip, one need merely push on the handle to move the front wall 256 closer to the rear wall 250, bringing the walls in close proximity to the new strip, and such a configurationis illustrated by dashed lines at 270.

In order to prevent the master strip 12 from rubbing against itself, thereby unnecessarily wearing, air is flowed through the loop chamber by introducing the air into the bottom of the chamber through the space 272 between the bottom housing ledge 266 and bottom chamber wall 264, as indicated by the arrows 274 in FIG. 14, to form an air bearing for the strip 12. Air can also be introduced at spaced locations elsewhere in the chamber, such as indicated at 276 and 278 to coast with the upflowing air to add turbulence and maintain the master strip 12 in a suspended, open looped configuration. The flow of air is from the bottom to the top loop chamber and the-air impinges against the bottom of the top wall 26, escaping generally through the spacebetween the top wall 26 and top edge of the front wall Referring additionally to FIG. 1, a further embodiment is illustrated. The top wall 26 is formedwith a pair of slots shown by dashed lines at 274 and 276, which are at opposite ends of the chamber and which lay immediately beneath the open ends of the buffer chamber 36 and 44, respectively. Air from the loopchamber escapes through the slots 274 and 276 and is directed as a blast against the master strip 12 to bias the master strip into the buffer chambers 36 and 44. While this bias is not needed during operation of the apparatus, at

startup it aids in carrying the master strip 12 into the buffer chambers, avoiding handling of the master strip 12. I

. It will be seen that the various embodiments discontinuously moving light sensitive duplicate strip,

comprising an exposure zone and means-for moving said master and duplicate strips in close contact through said exposure zone, the provision of:

a lamp assembly in said. exposure zone for exposing said master and duplicate strips, said lamp assembly comprising a lamp and reflector for said lamp, said reflector having a substantially greater length dimension than width dimension, and means for securing said reflector with its length dimension along the line of travel of said strips thereat,to define'a beam of light of first width in said line of travel, and for rotating said reflector and securing said reflector with its width dimen'sion along said line of travel to define a beam of light of second width in said line of travel. I 

1. In apparatus for contact duplicating information carried by a continuously moving master strip onto a continuously moving light sensitive duplicate strip, comprising an expsoure zone and means for moving said master and duplicate strips in close contact through said exposure zone, the provision of: a lamp assembly in said exposure zone for exposing said master and duplicate strips, said lamp assembly comprising a lamp and reflector for said lamp, said reflector having a substantially greater length dimension than width dimension, and means for securing said reflector with its length dimension along the line of travel of said strips thereat, to define a beam of light of first width in said line of travel, and for rotating said reflector and securing said reflector with its width dimension along said line of travel to define a beam of light of second width in said line of travel. 